The present disclosure described herein relates to a semiconductor memory, and more particularly, to a storage device including a nonvolatile memory and a memory controller, and an operating method of a retiming circuit that interfaces communications between the nonvolatile memory and the memory controller.
A storage device is a device that stores data according to a control of a host device, such as a computer, a smart phone, a smart pad, and so on. The storage device may contain a device which stores data on a magnetic disk such as a Hard Disk Drive, or a device which stores data on a semiconductor memory, in particular on a nonvolatile memory, such as a Solid State Drive (SSD) or a memory card.
A nonvolatile memory may be a Read Only Memory (ROM), a Programmable ROM (PROM), an Electrically Programmable ROM (EPROM), an Electrically Erasable and Programmable ROM (EEPROM), a flash memory, a Phase-change RAM (PRAM), a Magnetic RAM (MRAM), a Resistive RAM (RRAM), or a Ferroelectric RAM (FRAM).
Advancements in semiconductor fabrication technology have enabled a continued increase in the capacity of a solid state drive. As example, increase capacity may be accomplished through overlapping of semiconductor memory chips and increased integration of a semiconductor memory chip.
Generally, however, an increase in the capacity of the solid state drive hinders the reliability of a storage device. For example, the higher the number of semiconductor chips that are overlapped, the greater are certain resistance components of the overlapped chips. A toggle speed of a channel that is used to communicate with the semiconductor chips is hindered due to the increase in resistance components, thereby resulting in an increase in skew. In particular, the increase in skew may hinder the reliability of the storage device as the storage device operates at high speed.